Applying viscous materials, for example adhesives, to component edges makes high demands on the application mechanism because only slight deviations from the edge guides can be tolerated, and complete wetting of the component edge is to be achieved. For example, component edges on milled carbon fibre reinforced plastic (CFRP) components need to be sealed to provide protection against corrosion. Sealing can take place manually, in an automated manner or in a partly automated manner with the use of a suitable applicator.
High clock rates require an automated or partly-automated solution, for example with the use of a robot, because manual sealing is too time-consuming and consequently not cost-effective. Frequently, applicators hitherto used for automated adhesive application are associated with a disadvantage in that in the case of components subject to tolerances, the nozzle cannot follow the deviations of the component edge. This results in undesirable contact of the nozzle with the component, or in excessive spacing from the component in the case of a predetermined robot path. Furthermore, many conventional applicators and nozzles are unable to operate in narrow breakthroughs in the component.
There is a further problem in that the edges of modern composite materials, e.g. CFRP, have different edge widths as a result of their variable design. Programming a robot path for central alignment of the applicator is correspondingly expensive. While there is the option of using a suitable sensor system that transmits correction signals for height correction and if applicable for lateral correction directly to the robot control system, it is, however, necessary for there to be adequate space for the sensor system. Moreover, a sensor control system is costly, complex, and can cause considerable delay times.
In addition, during the application of adhesive there is a problem in that in the case of narrow component edges, despite the use of wide-slot nozzles, in the hitherto-used nozzles the applied adhesive bead usually has a semi-circular shape, and consequently the edges of the component surfaces are often not wetted. However, edge sealing providing full wetting of the surface would require a lenticular cross-sectional shape or the shape of a flat segment of a circle.
Because of the above-mentioned problems the component edges on milled CFRP-components with limited accessibility and on component breakthroughs have hitherto usually been sealed manually. Component edges with very tight radii and breakthroughs are exclusively sealed manually. In this process the adhesives are applied manually with paint brushes or from cartridges. After this, the semicircular adhesive bead is distributed on the component edge with the use of a roller, and excess adhesive, which runs off on the sides of the component, or on surfaces that do not require wetting, are cleaned manually.
U.S. Pat. No. 4,778,642 shows a nozzle for applying a viscous material, which nozzle has several additional nozzle apertures for influencing the application of material by means of an air stream. In this design the nozzle aperture for the application of material is encompassed by four air nozzles which during the application of material blow obliquely into the material strand emanating from the nozzle, and in so doing form said material strand already prior to application. Such a technique is also known from so-called whirling nozzles. Furthermore, in the nozzle which forms the subject of this printed publication further air nozzles are arranged at greater spacing from the nozzle aperture for the application of material, which further air nozzles act on the form of the already applied material bead. The problems associated with the application of a viscous material to component edges and in confined component breakthroughs or to component edges with tight radii are not addressed in this printed publication. Nor is the nozzle shown, because of its size determined by the various nozzle openings, suitable for such applications.
It is the object of the present invention to state a nozzle and a device for applying a viscous material, particularly an adhesive, to component edges, which nozzle and device allow optimal wetting of the component edges and precise guidance of the nozzle along the component edges and are also suitable for tight radii and component breakthroughs.